phone is extremely laggy with AOKP ROM

I just bought a new One V, which I am using as an mp3 player (haven't activated it as a phone). I rooted it and tried the CM10 ROM, but it was crashing when I tried to access settings. So I flashed AOKP ROM, and the device keeps hanging. I tried Mortplayer and JetAudio. The phone appears to be very slow and screens lock up. Do you think that this is due to the ROM? It will be hard to make use of this device as an mp3 player with this poor performance. Would I likely have better performance going back to the stock ROM? Where can I obtain the stock ROM?

Thanks. I did do a factory reset and cache/dalvik cache wipe. Unfortunately, I never backed up the stock ROM before proceeding. I have since flashed a few different custom ROMs but that has not solved the problem. I will follow those instructions after I find a stock ROM image. Do you know where I can find one? I Googled it but only found GSM versions.
Thanks again.

Re: moving the thread - I was wondering which forum to post this in to begin with...
My phone is branded as a Virgin Mobile phone, but again, I'm using it as an mp3 player. Does it matter whether I use the Sprint or Cricket ROM?
I don't know what the implications of the branding are.
Thanks again,